The use of electronic locks in industries such as the hotel industry and others is increasing. Electronic locks provide for increased security since the lock can be reprogrammed so that it will not accept keys which it would previously accept. This is important in the hotel industry, for example, in which access to a room by a former guest should be prevented. It can also be important in plants in which certain areas of the plant will have limited access, taking on more importance when an employee leaves.
An electronic lock and key system also has the advantage of not using a mechanical key which can be easily duplicated.
While existing electronic locks and keys have many advantages over mechanical locks and keys, some problems remain. One of these problems relates to the security of the system. Most keys used in electronic lock and key system employ a memory circuit in the key which is interrogated by the electronic lock. It is entirely possible for such a memory circuit to be interrogated by an enterprising thief to compromise the security of the electronic lock and key system.
Another problem with existing lock and key systems is the amount of power needed by the lock for operation. If powered by a battery, such locks cause the battery to have a low battery life such that the battery needs to be frequently replaced.
A still further problem with existing lock and key systems relates to the ease of programmability of the lock. The known systems require a bulky programming unit which must be physically transported from lock to lock in order to reprogram the lock.
Another problem noted with existing electronic locks is the installation of the lock electronics (or some portion of them) on the outside of the door. This compromises security of the lock, as well as detracts from the aesthetic appeal of the door.
With known electronic locks, the entire lock mechanism within a door would need to be replaced and the door modified in order to accommodate the use of the electronic lock. This does not allow for the retrofitting of existing doors to have an electronic lock, without incurring a relatively great expense.
In known electronic lock and key systems, the key is made to operate only the electronic lock of the system. However, it is useful to operate a variety of different locks with a single key, and some of these locks may be mechanical. It would therefore be advantageous for a key to be able to operate both an electronic lock as well as cut for use in conventional mechanical locks.
With electronic locks, there is occasionally the need for the supplying of external emergency power to operate the lock/key. However, this raises the possibility of the compromising of the security of access. There is thus a need for a lock/key which can be supplied with power externally in an emergency, without compromising security of access.
There is a need for a lock and key system which solves the above-described problems and presents a system that ensures the security of a system while providing the flexible features of an electronic lock and key system.